Yes. While alcohol withdrawal symptomsare often mild—pronounced sweating, hand tremors, and nausea, for example—more severe cases can critically damage the nervous system. That can lead to seizures, heart attack, and other life-threatening conditions. Symptoms of alcohol withdrawal generally stem from the fact that heavy drinking forces changes in the brain's sensitivity to key neurotransmitters. When someone stops drinking all of a sudden, the rebound effect can be deadly.

The most severe effect of this rebound is known as delirium tremens, meaning "shaking frenzy" in Latin. This develops in about 5 percent of patients hospitalized for alcohol withdrawal and kills about 5 percent of those who develop it. (Timely diagnosis and treatment, however, can reduce the mortality risk to around 1 out of every 2,000 hospitalized patients.) Symptoms of delirium tremens, also known as "the DTs," include floating in and out of consciousness, hallucinations, seizures, nausea, and diarrhea. The condition also impairs the autonomic nervous system, and a history of other drug use increases the risk for alcohol-related seizures.

Those newly on the wagon are also at risk of dying from Wernicke's encephalopathy, a form of brain damage caused by caused by thiamine (a.k.a. vitamin B1) deficiency. Alcohol hampers the body's ability to absorb thiamine from food, and over time can lead to the destruction of brain tissue. In the long run, quitting alcohol would reduce the risk of mortality, but the symptoms of encephalopathy—memory loss and impaired control over muscle and eye movement—may be mistaken for the general symptoms of withdrawal. If left untreated, Wernicke's encephalopathy leads to death roughly 20 percent of the time.